Calculate the number of unit cells is 8.1 g of aluminium if it crystallizes in a face-centered cubic (f.c.c) structure . (Atomic mass of Al =27 "g mol"^(-1))

Calculate the number of unit cells is 8.1 g of aluminium if it crystal

1.	Calculate the number of unit cells is 8.1 g of aluminium if it crystallizes in a face-centered cubic (f.c.c) structure . (Atomic mass of Al =27 "g mol"^(-1))
Answer» Solution :1 mole of AL=27 g `=6.02xx10^23` atoms `therefore` No. of Al atoms present in 8.1 g of Al`=(6.02xx10^23)/27xx8.1=1.806xx10^23` As face-centered CUBIC cell contains 4 atoms , therefore, number of unit CELLS present =`(1.806xx10^23)/4=4.515xx10^22`